ORLANDO, Fla. (AP) — The NBA remains the leader among professional sports leagues in diversity hiring practices, according to a report released Tuesday.

The University of Central Florida's Institute of Diversity and Ethics in Sport gave the NBA an A-plus for racial hiring and A-minus for gender hiring in its annual Racial and Gender Report Card. The league received an overall grade of A.

It is the third straight report that the NBA has scored at least an A for both race and gender.

Primary study author Richard Lapchick said NBA Commissioner David Stern's leadership is one of the biggest reasons why the league continues to be a model in diversity from front office executives to coaches and players.

"I think everybody else changed over the years because of pressure, but I think the NBA started with David Stern to apply its own internal pressure to make the league office and teams look more like America," Lapchick said. "Because he's been so respected for so long from pretty much everybody involved in NBA and in other leagues, it has heightened his status even further. They know what his priorities are and try to implement them."

For the first time in NBA history, there were more head coaches of color (53 percent) than white head coaches. Also, African-Americans comprised 47 percent of all NBA coaches, the highest percentage since the 2001-02 season.

The 20-percentage point increase in coaches of color was the greatest for people of color in any position in 2011-2012.

"Having that many coaches of color is big. I'm not sure I thought I'd see that day," Lapchick said.

In the NBA league office, 34 percent of all professional employees are people of color and 42 percent are women. There were also six more women in vice president positions at the league office during the 2011-2012 season than in last year's report, increasing the total to 39 positions.

Lapchick said that though the NBA consistently has outpaced other major professional leagues, they still have some room to improve when it comes to gender hiring at the team level, where women make up 18 percent of vice president and 25 percent of senior administrator positions.

But he also noted that the increasing presence of women and minorities of color in ownership roles would surely lead to improvement because "they bring their life experiences and knowledge of qualified people" to their jobs. There were 20 people of color with ownership stakes in teams this past season and 15 women in ownership roles.

It's also why Lapchick said he believes the NBA has avoided instituting mandates like the NFL's Rooney Rule, which mandates teams interview a minority for open coaching positions.

"I once had a conversation with Stern in which he said he wanted to get to the stage when no one notices when you hire a person of color or when they fire a person of color," Lapchick said. "He said he wanted it to be that people would see they were just trying to hire the best person. That's permeated through the league and something I hope a lot of people will take note of."